This invention relates to rechargeable or secondary batteries and, in particular, to rechargeable or secondary batteries using zinc negative electrodes.
U.S. Pat. No. 5,460,899 and U.S. patent application Ser. No. 08/431,556, now U.S. Pat. No. 5,556,720, assigned to the same assignee hereof, disclose zinc secondary batteries in which the zinc negative electrode is formed from first and second electrode assemblies separated by a porous hydrophobic element. Each electrode assembly includes an active zinc element, comprised of zinc active material, a Ba(OH).sub.2, Sr(OH).sub.2 or Ca(OH).sub.2 material and a conductive matrix formed with a metallic oxide.
Each electrode assembly further includes a metallic current collector abutting the zinc active element and a gas recombination catalytic element formed from a material more electropositive than zinc and having a chemical or electrochemical affinity for reacting with oxygen. The aforesaid gas recombination catalytic element of each electrode assembly abuts the hydrophobic element. The latter element and the electrode assemblies are enveloped by a separator material to complete the electrode.
The aforesaid zinc negative electrode, while advantageous, utilizes many elements, including a gas recombination catalytic element, in each electrode assembly. Accordingly, reducing the number of elements in the zinc electrode would be desirable, both from a fabrication and a cost standpoint.
It is, therefore, an object of the present invention to provide a zinc negative electrode of the above type which is of simpler construction.
It is a further object of the present invention to provide a zinc negative electrode of the above type having a reduced number of elements.